#MonthOfCode day 12 - pixel

day_12.py

import pygame
from time import sleep
import random
import sys

BLACK = ( 0, 0, 0)
NB_PIX_BATCH = 64
DISP_WIDTH = 640
DISP_HEIGHT = 480
REFR_RATE = 0.008

class MovingPix():
    def __init__(self , x,y):
        self.x = float( x)
        self.y = float( y)

        #random color and speed
        self.color= tuple( [random.randint(64,255) for i in xrange(3) ]  )
        self.x_speed = random.choice( (-1,1) ) * 256.0 * random.random()
        self.y_speed = -1.0 * 380.0 * random.random()
        self.disp_x, self.disp_y = int(self.x), int(self.y)

    def isOut( self):
        #we calculate the next pos
        #is it out of bounds?
        return( self.disp_y>=DISP_HEIGHT-1
            or self.disp_x>=DISP_WIDTH-1
            or self.disp_x<1
            or self.disp_y<1  )

    def move(self, delay):
        self.x += (self.x_speed * delay)
        self.y += (self.y_speed * delay)
        self.y_speed += (700.0 * delay )   # simulates gravity
        new_x, new_y = int(round(self.x)), int(round(self.y))
        self.disp_x, self.disp_y = new_x, new_y
    
    def display(self, window):
        window.set_at((self.disp_x, self.disp_y), self.color)
        window.set_at((self.disp_x-1, self.disp_y), self.color)
        window.set_at((self.disp_x+1, self.disp_y), self.color)
        window.set_at((self.disp_x, self.disp_y-1), self.color)
        window.set_at((self.disp_x, self.disp_y+1), self.color)

        window.set_at((self.disp_x-1, self.disp_y-1), self.color)
        window.set_at((self.disp_x+1, self.disp_y-1), self.color)
        window.set_at((self.disp_x-1, self.disp_y+1), self.color)
        window.set_at((self.disp_x+1, self.disp_y+1), self.color)

def refreshScreen():
    window.fill( BLACK )
    for pix in pixel_list:
        pix.display( window)
    pygame.display.flip() 

# init. pygame libr; create the screen and diplays a help message in the console
pygame.init() 
window = pygame.display.set_mode( (DISP_WIDTH, DISP_HEIGHT) )

# diplays the state and then loops for input handling 
pixel_list = list()
pix_to_gen = 0
while True: 
    for event in pygame.event.get(): 
        if event.type == pygame.QUIT: 
            sys.exit(0) 
        if event.type == pygame.MOUSEBUTTONDOWN :
            m_pos = pygame.mouse.get_pos()
            pix_to_gen = NB_PIX_BATCH

    # adding and removing pixels from the list
    for pix in pixel_list:
        pix.move( REFR_RATE )
        if( pix.isOut() ):
            pixel_list.remove(pix )
    if( pix_to_gen>0):
        pixel_list.append( MovingPix( *m_pos) )
        pix_to_gen-=1

    # display
    refreshScreen()
    sleep( REFR_RATE )